Validated Spectrophotometric Methods for the Determination of Oxybuprocaine Hydrochloride

Simple, rapid, accurate and reliable spectrophotometric methods were developed and validated for determination of Oxybuprocaine hydrochloride (OXY) in pure form and in pharmaceutical preparation. The methods depend on charge transfer reaction of OXY as n-electron donor with p-chloranilic acid (p-CA), 2, 3 ? dichloro 5, 6 ? dicyano 1, 4 benzoquinone (DDQ) and iodine as π and σ acceptors, respectively. These reactions were studied under various conditions and the optimum parameters were selected. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9996, 0.9997, and 0.9998) were found between absorbance of the formed complexes and concentrations of OXY in the range of 20.0 - 220.0 μg/mL, 10.0-80.0 μg/mL and 4.0-44.0 μg/mL for (p-CA), DDQ and iodine methods, respectively. The methods were successfully applied for the determination of OXY in pure form and in dosage form. Job’s method was applied to determine the stoichiometry of the reactions. No significant difference was found at p = 0.05 when the obtained results of the proposed methods were statistically compared with those obtained by an official method.